Hematology and Clinical Microscopy Glossary - College of American ...
Hematology and Clinical Microscopy Glossary - College of American ...
Hematology and Clinical Microscopy Glossary - College of American ...
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Cerebrospinal Fluid (CSF) <strong>and</strong> Body Fluid Cell Identification<br />
abundant, basophilic <strong>and</strong> agranular. Often it shows an<br />
uneven or grainy texture. Degenerative changes may<br />
occur including multiple small vacuoles or cytoplasmic<br />
blebs. Overall, the appearance <strong>of</strong> synovial lining cells<br />
is similar to that <strong>of</strong> mesothelial cells in serous fluids. Their<br />
presence in synovial fluid is expected <strong>and</strong> has no<br />
diagnostic significance.<br />
Ventricular Lining Cell (Ependymal or<br />
Choroid Cell)<br />
Cells lining the ventricles (ependymal cells) or choroid<br />
plexus (choroidal cells or choroid plexus cells) may be<br />
shed into the CSF, particularly in neonates or in the<br />
presence <strong>of</strong> a ventricular shunt or reservoir. Choroidal<br />
<strong>and</strong> ependymal cells are not diagnostically significant<br />
but must be distinguished from malignant cells.<br />
These large (20 to 40 μm) cells may occur singly or in<br />
clumps. Clumps may be loose aggregates or may be<br />
tissue with indistinct cell borders. Nuclei are eccentrically<br />
placed <strong>and</strong> are round to oval with a definitive smooth<br />
nuclear membrane <strong>and</strong> regular nuclear contour.<br />
Chromatin is distributed evenly <strong>and</strong> is reticulated or<br />
dense; occasionally the nucleus may appear pyknotic.<br />
Nucleoli are inconspicuous. The cytoplasm is typically<br />
amphophilic <strong>and</strong> grainy but occasionally is blue (a<br />
feature <strong>of</strong> ependymal cells). Microvilli may be present<br />
(a feature <strong>of</strong> choroidal cells). Extensive degeneration <strong>of</strong><br />
choroidal <strong>and</strong> ependymal cells may occur so that only<br />
naked nuclei remain.<br />
Miscellaneous Cells<br />
Blast Cell<br />
A blast is a large, round to oval cell, 10 to 20 μm in<br />
diameter, with a high nuclear-to-cytoplasmic ratio. The<br />
blast <strong>of</strong>ten has a round to oval nucleus, but it is<br />
sometimes indented or folded. In addition,<br />
cytocentrifugation artifact may result in an irregular<br />
nuclear contour. The nuclear chromatin is typically fine,<br />
lacey, or granular <strong>and</strong> one or more nucleoli may be<br />
present Nucleoli are more prominent in cytocentrifuge<br />
slides. The cytoplasm is basophilic <strong>and</strong> <strong>of</strong>ten agranular;<br />
however, when cytoplasmic granules occur, they are<br />
more easily visualized in the cytocentrifuge slide than in<br />
peripheral blood or bone marrow smears. In the<br />
absence <strong>of</strong> lineage-associated findings, such as Auer<br />
rods, cytoplasmic granules, cytochemical data, or cell<br />
surface marker data, it is not possible to further<br />
characterize a given blast cell. This is particularly<br />
true for body fluids, where cytospin preparation<br />
artifact may alter or obscure morphologic details.<br />
Degenerative changes also may occur if the fluid<br />
specimen is not processed promptly.<br />
Chondrocyte (Cartilage Cell)<br />
Rarely, chondrocytes are obtained during lumbar<br />
puncture, probably when the needle nicks the<br />
vertebral cartilage. This is a more common occurrence<br />
in infants <strong>of</strong> adults with a narrow intervertebral space.<br />
Chondrocytes are typically seen in the synovial fluid <strong>of</strong><br />
patients with osteoarthritis, but also may occur after joint<br />
trauma or surgery.<br />
The cells have round or oval, dark nuclei which are<br />
typically centrally placed. The cytoplasm is dense <strong>and</strong><br />
wine-red. A cytoplasmic clear zone adjacent to the<br />
nucleus is <strong>of</strong>ten present <strong>and</strong> it may completely surround<br />
the nucleus.<br />
Degenerating Cells (Not Otherwise<br />
Specified)<br />
Degenerating cells with pyknotic (highly condensed)<br />
nuclei or nuclear karyorrhexis (fragmentation) may<br />
occasionally be seen in body fluids. Autodigestion or<br />
autolysis <strong>of</strong> neutrophils may occur as they attempt to<br />
remove foreign material.<br />
The nucleus becomes pyknotic <strong>and</strong> fragments <strong>and</strong> with<br />
further autolysis, may appear as one or more indistinct,<br />
light purple inclusion(s). The nuclear lobes may fragment<br />
into numerous small particles <strong>of</strong> varying sizes that<br />
resemble microorganisms. Cytoplasmic granules may<br />
become less prominent or may fuse (particularly with<br />
toxic granulation). The cytoplasmic borders may<br />
become ftayed <strong>and</strong> indistinct. Cytoplasmic vacuole<br />
formation is common.<br />
Autolytic neutrophils with eccentric, dense, round nuclei<br />
<strong>and</strong> pale cytoplasm may resemble nucleated red cells,<br />
but differ from them in the persistence <strong>of</strong> cytoplasmic<br />
granules.<br />
Actively dividing cells such as malignant cells, reactive<br />
lymphocytes <strong>and</strong> mesothelial cells, may more<br />
readily undergo degenerative changes in body fluids.<br />
The cytoplasm may show a swollen, vacuolated, or<br />
frayed appearance. The nuclear chromatin may<br />
show coarse condensations separated by enlarged<br />
parachromatin spaces (salami-like appearance).<br />
Ventricular lining cells <strong>of</strong>ten will not appear intact when<br />
shed into CSF or ventricular fluid; only bare nuclei with<br />
pieces <strong>of</strong> frayed cytoplasm will be seen.<br />
52 <strong>College</strong> <strong>of</strong> <strong>American</strong> Pathologists<br />
2012 <strong>Hematology</strong>, <strong>Clinical</strong> <strong>Microscopy</strong>, <strong>and</strong> Body Fluids <strong>Glossary</strong>